Fizz, Foam, or Nothing? Investigating Chemical Reactions with Baking Soda and Vinegar
Science Lab · Grade 5 · Science · ngss
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Type
science_lab
Pre Lab
Background: Have you ever mixed baking soda and vinegar and watched it fizz and bubble? That dramatic reaction is not just mixing — it is a **chemical reaction**. A **chemical reaction** is a process in which two or more substances, called **reactants**, combine and are transformed into one or more entirely new substances called **products**. The products have different properties than the original reactants. In the baking soda and vinegar reaction, the reactants are baking soda (sodium bicarbonate) and vinegar (acetic acid). The products include water, sodium acetate, and carbon dioxide gas — that is the fizzing you see! The gas bubbles are proof that something brand new has been created.
Scientists look for specific **evidence of a chemical reaction** to know that a new substance has formed. These signs include the production of a gas (bubbles), a change in color, a change in temperature, the formation of a solid (called a **precipitate**), or the production of light or sound. Just because something looks different does not automatically mean a chemical reaction occurred — for example, dissolving sugar in water changes its appearance but does NOT produce a new substance. Scientists must use careful observation and measurement, not just their eyes, to tell the difference.
One of the most important ideas in science is the **Law of Conservation of Mass**, which states that matter is never created or destroyed during a chemical or physical change — it is only rearranged. Even when a gas floats away or a solid disappears, the total **mass** (weight) of all the matter involved stays the same. In today's lab, you will plan and carry out a controlled investigation to explore how changing the amount of baking soda affects a chemical reaction with vinegar. You will also weigh your materials before and after to test whether mass is truly conserved.
Vocabulary
Term: Chemical reaction
Definition: A process in which reactants are transformed into new substances called products, which have different properties than the original materials.
Term: Reactant
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